FLASH Investigations Using Protons: Design of Delivery System, Preclinical Setup and Confirmation of FLASH Effect...

Area of Science:

• Medical Physics
• Radiation Oncology
• Preclinical Research

Background:

• Ultra-high dose rate irradiation, known as FLASH therapy, demonstrates reduced normal tissue toxicity compared to conventional dose rates.
• FLASH effects are observed at dose rates exceeding 40 Gy/s, with studies primarily using photon, electron, or some proton beams.

Purpose of the Study:

• To develop and characterize a proton irradiation platform for FLASH therapy within a clinical proton facility.
• To establish dosimetry methods for precise dose delivery at ultra-high dose rates.
• To investigate the potential tissue-sparing effects of FLASH proton therapy in preclinical models.

Main Methods:

• Development of a proton irradiation platform utilizing a double-scattering system in a clinical proton facility.
• Optimization of the scattering system to achieve a homogeneous dose distribution over a large field size at dose rates >100 Gy/s.
• Characterization of proton beam properties (energy, dose rate, field size) using dosimetry methods.
• Application of the developed platform for dose-response studies in mice undergoing partial abdominal irradiation.

Main Results:

• Successful development of a proton irradiation platform capable of delivering dose rates of approximately 120 Gy/s.
• Achieved a collimated pencil beam with a 1.6 × 1.2 cm2 elliptical field size.
• Preliminary results from mouse studies suggest a potential tissue-sparing effect associated with FLASH irradiation.

Conclusions:

• The developed proton irradiation platform enables FLASH radiotherapy research in a clinical setting.
• FLASH proton therapy holds promise for reducing normal tissue toxicity in radiation oncology.
• Further preclinical and clinical investigations are warranted to fully elucidate the benefits of FLASH proton therapy.